At the time of travel (and perhaps still) the Laerdal Tunnel in Norway is the longest underground tunnel in the world used for traffic. Norwegians have become accustomed to using road tunnels to traverse the mountainous landscape they call home.
During the journey in the 24km tunnel there are areas with coloured lights every 8 or so km, to help keep drivers alert. Buses stop in here to show tourists the lights. We pulled over briefly to take this photograph.